Ask any adult in
your family if they know their hat size. Then, get some
string and a tape measure or ruler.

To determine their
hat size, use the string to measure the circumference or
length around the head. Place the string where a hat would
normally rest (above the eyebrows and ears.) Do not pull the
string too tight.

Mark or cut the
string to the length that you measured. Lay the string
beside a tape measure or ruler to see the inches. Compare
the inches to the hat sizes on the graph.